Method of improving thermal stability

ABSTRACT

The invention relates to a method of improving the thermal stability of natural or synthetic polyamide fibre materials that are undyed, fluorescent whitened or dyed with reactive or disperse dyes, with the exception of metal complex dyes, wherein the fibre material is treated with a liquor comprising a compound of formula (1) Y 1 —X—Y 2  (1) wherein X is a divalent aliphatic or cycloaliphatic radical and Y 1  and Y 2  are each independently of the other —OH, —CO—OR 1 , —NR 1 R 2 , —CO—NH—NR 1 R 2  or —NH—CO—NH—NR 1 R 2 , wherein R 1  and R 2  are each independently of the other hydrogen; Q-Ĉalkyl unsubstituted or substituted by one or more hydroxy, amino or carboxyl groups or halogen atoms; C 5 -C 24 -aryl unsubstituted or substituted by one or more hydroxy, amino or carboxyl groups or halogen atoms; C 6 -C 36 aralkyl unsubstituted or substituted by one or more hydroxy, amino or carboxyl groups or halogen atoms; or C 5 -C 24 cycloalkyl unsubstituted or substituted by one or more hydroxy, amino or carboxyl groups or halogen atoms.

The present invention relates to a method of improving the thermalstability of undyed, fluorescent whitened or dyed, natural or syntheticpolyamide fibre materials and to a textile auxiliary for use in thatmethod.

In various textile-processing procedures (pretreatment, application offluorescent whitening agents, dyeing, finishing), polyamide fibrematerials are exposed to a heat treatment. Particularly in the case ofundyed goods and goods which may have been fluorescent whitened, thisfrequently results in undesirable yellowing.

The action of heat also often results in undesirable effects before andafter dyeing.

For example, a thermal pretreatment may lead to oxidative damage to thepolyamide, which manifests itself, for example, in increased yellowingor loss of tear strength or which may have an adverse effect ondyeability.

During and after the dyeing process, a thermal treatment may result inunacceptable alterations in shade.

It has now been found that the above-mentioned disadvantageous effectscan be substantially reduced by the use of a specific textile auxiliary.

The present invention relates to a method of improving the thermalstability of natural or synthetic polyamide fibre materials that areundyed, fluorescent whitened or dyed with reactive or disperse dyes,with the exception of metal complex dyes, wherein the fibre material istreated with a liquor comprising a compound of formula (1)

YrX—Y₂  (1)

wherein X is a divalent aliphatic or cycloaliphatic radical andYi and Y₂ are each independently of the other —OH, —CO—ORi, —NRiR₂,—CO—NH—NRiR₂ or —NH—CO—NH—NR₁R₂,wherein Ri and R₂ are each independently of the other hydrogen;Ci-Ci₂alkyl unsubstituted or substituted by one or more hydroxy, aminoor carboxyl groups or halogen atoms; C₅-C₂₄-aryl unsubstituted orsubstituted by one or more hydroxy, amino or carboxyl groups or halogenatoms; C₆-C₃₆aralkyl unsubstituted or substituted by one or morehydroxy, amino or carboxyl groups or halogen atoms; or C₅-C₂₄CyClOalkylunsubstituted or substituted by one or more hydroxy, amino or carboxylgroups or halogen atoms.

Aliphatic radicals X in formula (I) are, for example, ethylene,propylene, trimethylene, propane-1,1-diyl, tetramethylene,hexamethylene, octamethylene and decamethylene or linear or branchedalkylene that is interrupted by one or more O atoms or —NH—, —N(alkyl)-or —N(alkylene-NH₂)— groups.

Suitable cycloaliphatic radicals X are, for example,cyclohexane-1,2-diyl, cyclohexane-1,3-diyl and also

C_(r) Ci₂Alkyl as a radical Ri or R₂ can be, for example, methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,neopentyl, n-hexyl, n-octyl or n-dodecyl.

A C₅-C₂₄aryl group as one of the radicals Ri-R₅ is, for example, phenyl,tolyl, mesityl, isityl, naphthyl or anthryl.

Suitable C₆-C₃₆aralkyl groups are, for example, benzyl and2-phenylethyl.

Examples of C₅-C₂₄cycloalkyl are cyclopentyl and cyclohexyl.

In the method according to the invention, preference is given to the useof compounds of formula (1) wherein X is ethylene, tetramethylene,hexamethylene or octamethylene.

Preference is also given to compounds of formula (1) wherein Y₁ and Y₂are —NR₁R₂, —CO—NH—NR₁R₂ Or —NH—CO—NH—NR₁R₂, wherein R₁ and R₂ ishydrogen, C_(r) C₁₂alkyl or C₅-C₂₄aryl.

Special preference is given to compounds of formula (1) wherein Y₁ andY₂ are —NR₁R₂, —CO—NH—NR₁R₂ or —NH—CO—NH—NR₁R₂, wherein R₁ and R₂ arehydrogen, methyl or phenyl.

Examples of suitable compounds of general formula (1) are the compoundsof formulae (101)-(104)

The compounds of formula (1) are known and are commercially available orcan be synthesised by known methods.

The compounds of formula (1) used in the method according to theinvention are present in the liquor advantageously in an amount of from0.1 g/l to 100 g/l, preferably from 0.5 g/l to 50 g/l and especiallyfrom 1.0 g/l to 40 g/l.

As polyamide fibre material there comes into consideration naturalpolyamide fibre material, for example wool or silk, or syntheticpolyamide fibre material, for example polyamide 6 or polyamide 6.6, orblends, for example wool/cellulose, polyamide/cellulose, polyamide/wool,polyamide/polyester or, especially, polyamide/elastane blends. The fibrematerial is preferably synthetic polyamide fibre material.

The textile material can be used in any form, for example in the form offibre, yarn, woven fabric or knitted fabric.

The textile auxiliary according to the invention can be applied to thepolyamide fibre material by customary dyeing or printing methods, forexample by spray application or foam application, by the exhaust processor, preferably, the pad-dyeing process.

Special apparatus is not necessary. It is possible to use, for example,the customary dyeing apparatus, e.g. open baths, winch becks, jiggers orpaddle, jet or circulatory apparatus.

In addition to comprising water and the textile auxiliary, the liquorsmay comprise further additives, for example wetting agents, anti-foams,levelling agents or agents that influence the properties of the textilematerial, for example softeners, flame-proofing agents or dirt-, water-and oil-repellants and also water-softeners and natural or syntheticthickeners, e.g. alginates and cellulose ethers.

As mentioned above, the method according to the invention canadvantageously be used for the thermal stabilisation both of undyedpolyamide (white goods), which may have been treated with a fluorescentwhitening agent, and of dyed polyamide.

In the case of undyed or fluorescent whitened polyamide, the yellowingcaused by heat treatment during heat-setting (hot air) or duringmoulding processes (contact heat) is prevented or reduced.

The method according to the invention is especially effective in thetreatment of fluorescent whitened polyamide fibre material.

In the thermal stabilisation of dyed polyamide, the textile auxiliaryaccording to the invention can be applied before, during or afterdyeing.

When the auxiliary is used before dyeing, yellowing of the undyed goodsduring so-called pre-setting can be prevented or reduced. Furthermore,oxidative damage to the material during pre-setting, which can bringabout a change in the dye uptake, is prevented.

The textile auxiliary according to the invention is preferably appliedafter dyeing of the polyamide fibre material with reactive or dispersedyes, with the exception of metal complex dyes.

The after-treatment of the dyed polyamide material with the textileauxiliary according to the invention brings about especially a certaindegree of fibre protection during post-setting (heat setting) andeffectively reduces the alteration in shade that frequently occurs inthat process step, that is to say the shade remains constant, there isno dulling and no loss of colour strength.

In the case of undyed or fluorescent whitened polyamide materials, noappreciable reduction in whiteness is observed after the treatment withthe textile auxiliary according to the invention.

It has also been found that, surprisingly, the treatment of thepolyamide fibre material with the textile auxiliary according to theinvention also brings about an improvement in fastness to ozone, NO_(x)and chlorine.

The invention accordingly relates also to a method of improving thefastness to ozone, NO_(x) and chlorine of natural or synthetic polyamidefibre materials that are undyed, fluorescent whitened or dyed withreactive or disperse dyes, with the exception of metal complex dyes,wherein the fibre material is treated with a liquor comprising acompound of formula (1), as defined above.

So-called storage yellowing, that is to say the yellowing that occursduring storage of the textile materials, can surprisingly also beeffectively reduced by treatment with the textile auxiliary according tothe invention. Resistance to storage yellowing is generally measuredusing the Courtaulds yellowing test. The polyamide fibre materialstreated with the textile auxiliary according to the invention have ahigh Courtaulds fastness.

The textile auxiliaries according to the invention may comprise asfurther additives, for example, wetting agents, dispersants or pHregulators.

The following Examples serve to illustrate the invention. Unlessotherwise indicated, temperatures are given in degrees Celsius, partsare parts by weight and percentages relate to percent by weight. Partsby weight relate to parts by volume in a ratio of kilograms to litres.

EXAMPLE 1 Treatment of Fluorescent Whitened Polyamide (a) WhiteningProcess

A PA 6.6 textured tricot is treated by the exhaust process with anaqueous liquor containing 2.0% Uvitex® NFW liquid (fluorescent whitener,Ciba Specialty Chemicals) and 1.0 g/l of Ultravon® EL (dispersant, CibaSpecialty Chemicals). The pH is adjusted to 4.5 with acetic acid.

Liquor ratio 1:20, 30 min/95° C.

(b) Application of Auxiliary

The whitened fabric is treated by the pad-dyeing process with an aqueousliquor containing different amounts of adipic acid dihydrazide.

Liquor pick-up 100%; drying at 70° C.Whiteness according to Ganz: 230

The fabric is then subjected to a moulding test (30 s/210° C. and 60s/210° C.); the whiteness values measured after the moulding test aregiven in Table 1:

TABLE 1 Adipic acid dihydrazide [g/l] Moulding Whiteness (Ganz) 0 30s/210° C. 152 0 60 s/210° C. 93 2 30 s/210° C. 198 2 60 s/210° C. 178 430 s/210° C. 205 4 60 s/210° C. 193 8 30 s/210° C. 208 8 60 s/210° C.200 12 30 s/210° C. 208 12 30 s/210° C. 202

EXAMPLE 2 Treatment of Dyed Polyamide

A PA 6.6 textured tricot is dyed by the exhaust process with an aqueousliquor containing 0.02% Tectilon® Red 2B (Ciba Specialty Chemicals).

The fabric is then treated by the pad-dyeing process with an aqueousliquor containing 20 g/l of adipic acid dihydrazide (liquor pick-up100%; pH=4-5), dried for 2 min at 120° C. and then subjected toheat-setting under different conditions. Table 2 gives the deviations inshade (DEF values) in comparison with the reference (untreated dyedfabric).

TABLE 2 Reference Adipic acid dihydrazide [DEF] [DEF] Untreated 0 Dried0.53 0.67 Set 60 s/195° C. 2.80 1.06 Set 30 s/210° C. 3.72 1.31 Set 120s/210° C. 12.40 3.15 Set 240 s/210° C. 17.98 4.70

EXAMPLE 3 Treatment of Dyed Polyamide

A PA 6.6 textured tricot is dyed by the exhaust process with an aqueousliquor containing 0.65% Terasil® Flavin 8GFF (Ciba Specialty Chemicals).

The fabric is then treated by the pad-dyeing process with an aqueousliquor containing 20 g/l of adipic acid dihydrazide (liquor pick-up100%; pH=4-5), dried for 2 min at 120° C. and then subjected toheat-setting under different conditions. Table 3 shows the deviations inshade (DEF values) in comparison with the reference (untreated dyedfabric).

TABLE 3 Reference Adipic acid dihydrazide [DEF] [DEF] Untreated 0 Dried0.20 1.23 Set 60 s/195° C. 4.80 2.18 Set 30 s/210° C. 5.95 3.18 Set 120s/210° C. 21.44 6.91 Set 240 s/210° C. 32.35 8.99

EXAMPLE 4 Application to White Goods

A PA 6.6 textured tricot is, as described in Example 3, treated by thepad-dyeing process with an aqueous liquor containing 20 g/l of adipicacid dihydrazide (liquor pick-up 100%; pH=4-5), dried for 2 min at 120°C. and then subjected to heat-setting under different conditions. Table4 shows the whiteness values (Ganz) in comparison with the reference(untreated fabric).

TABLE 4 Reference Adipic acid dihydrazide whiteness (Ganz) whiteness(Ganz) Untreated 67.7 Dried 68.3 62.7 Set 60 s/195° C. 28.4 59.7 Set 30s/210° C. 13.5 44.4 Set 120 s/210° C. −73.6 22.6 Set 240 s/210° C.−157.7 −11.1

EXAMPLE 5 Wash-Fastness of the Auxiliary

As described in Example 4, a PA 6.6 textured tricot is treated with anaqueous liquor containing 20 g/l of adipic acid dihydrazide (ADH).Samples of the treated fabric are then washed three times, six times andten times.

After a moulding test, the whiteness according to Ganz is measured(Table 5).

TABLE 5 Moulding Whiteness (Ganz) Whiteness (Ganz) reference (untreated)treated with ADH Washing 40° C. 3× 6× 10× 3× 6× 10× Set 30 s/210° C.27.6 19.2 23.0 39.9 41.4 40.1 Set 120 s/210° C. −114.1 −127.5 −136.9 8.510.1 −4.1 Set 240 s/210° C. −140.0 −129.9 −136.4 2.4 9.7 2.4

EXAMPLE 6 Moulding Fastness of Dyed Polyamide

A PA 6.6 textured tricot is, as described in Example 2, dyed withTectilon® Red 2B and then treated with adipic acid dihydrazide. Afterthe moulding test, the deviations in shade (DEF values) in comparisonwith the reference (untreated dyed fabric) are measured (Table 6).

TABLE 6 Reference Adipic acid dihydrazide [DEF] [DEF] Untreated 0 Dried1.30 1.45 Set 60 s/195° C. 2.66 1.54 Set 30 s/210° C. 8.35 2.00 Set 120s/210° C. 12.83 3.25

EXAMPLE 7 Moulding Fastness of Dyed Polyamide

A PA 6.6 textured tricot is, as described in Example 4, dyed withTerasil® Flavin 8GFF and then treated with adipic acid dihydrazide.After the moulding test, the deviations in shade (DEF values) incomparison with the reference (untreated dyed fabric) are measured(Table 7).

TABLE 7 Reference Adipic acid dihydrazide [DEF] [DEF] Untreated 0 Dried0.52 1.45 Set 60 s/195° C. 4.25 2.22 Set 30 s/210° C. 4.84 3.13 Set 120s/210° C. 8.16 4.93

EXAMPLE 8 Moulding Fastness of Treated White Goods

A PA 6.6 textured tricot (white goods) is, as described in Example 4,treated with adipic acid dihydrazide. After the moulding test, thewhiteness (Ganz) in comparison with the reference (untreated fabric) ismeasured (Table 8).

TABLE 8 Reference Adipic acid dihydrazide whiteness (Ganz) whiteness(Ganz) Untreated 68.9 Dried 67.9 63.4 Set 60 s/195° C. 26.7 45.8 Set 30s/210° C. 16.8 41.8 Set 120 s/210° C. 1.1 27.4

EXAMPLE 9 Treatment of Fluorescent Whitened Polyamide

As described in Example 1, a PA 6.6 textured tricot is fluorescentwhitened with Uvitex® NFW liquid and then treated with adipic aciddihydrazide, dried at 60° C. and then subjected to heat-setting underdifferent conditions. Table 9 shows the measured whiteness valuesaccording to Ganz in comparison with the reference (fluorescent whitenedfabric, without ADH treatment).

TABLE 9 Whiteness Whiteness (reference) (ADH treatment) Untreated 243.6204.9 Set 30 s/190° C. 230.3 219.3 Set 60 s/190° C. 150.7 210.6 Set 30s/210° C. 174.6 216.5 Set 60 s/210° C. −38.2 204.8

EXAMPLE 10 Treatment of Fluorescent Whitened Polyamide

As described in Example 1, a PA 6.6 textured tricot is fluorescentwhitened with Uvitex® NFW liquid by the exhaust process. The fabric isthen treated by the exhaust process with an aqueous liquor containing2.0% N,N′-diphenylethylenediamine (DPEDA) (pH=5.0; liquor ratio 1:20; 30min/98° C.) and then subjected to heat-setting under differentconditions. Table 10 shows the measured whiteness values according toGanz in comparison with the reference (fluorescent whitened fabric,without DPEDA treatment).

TABLE 10 Whiteness Whiteness (reference) (DPEDA treatment) Untreated243.6 197.3 Set 30 s/190° C. 223.3 196.7 Set 60 s/190° C. 150.7 175.5Set 30 s/210° C. 174.6 179.8 Set 60 s/210° C. −38.2 128.7

1. A method of improving the thermal stability of natural or syntheticpolyamide fibre materials that are undyed, fluorescent whitened or dyedwith reactive or disperse dyes, with the exception of metal complexdyes, wherein the fibre material is treated with a liquor comprising acompound of formula (I)Y₁—X—Y₂  (1) wherein X is a divalent aliphatic or cycloaliphatic radicaland Y₁ and Y₂ are each independently of the other —OH, —CO—OR₁, —NR₁R₂,—CO—NH—NR₁R₂ or —NH—CO—NH—NR₁R₂, wherein R₁ and R₂ are eachindependently of the other hydrogen; C₁-C₁₂ alkyl unsubstituted orsubstituted by one or more hydroxy, amino or carboxyl groups or halogenatoms; C₅-C₂₄ aryl unsubstituted or substituted by one or more hydroxy,amino or carboxyl groups or halogen atoms; C₆-C₃₆ aralkyl unsubstitutedor substituted by one or more hydroxy, amino or carboxyl groups orhalogen atoms; or C₅-C₂₄ cycloalkyl unsubstituted or substituted by oneor more hydroxy, amino or carboxyl groups or halogen atoms.
 2. A methodaccording to claim 1 wherein X is ethylene, tetramethylene,hexamethylene or octamethylene.
 3. A method according to claim 1 whereinY₁ and Y₂ are —NR₁R₂, —CO—NH—NR₁R₂ or —NH—CO—NH—NR₁R₂, wherein R₁ and R₂are hydrogen, C₁-C₁₂ alkyl or C₅-C₂₄ aryl.
 4. A method according toclaim 1 wherein Y₁ and Y₂ are —NR₁R₂, —CO—NH—NR₁R₂ or —NH—CO—NH—NR₁R₂,wherein R₁ and R₂ are hydrogen, methyl or phenyl.
 5. A method accordingto claim 1 wherein the compound of formula (1) is a compound of formula(101)-(104)


6. A method according to claim 1 wherein the compound of formula (1) ispresent in the liquor in an amount of from 0.1 g/l to 100 g/l.
 7. Amethod according to claim 1 wherein the treatment of the fibre materialwith the liquor comprising a compound of formula (1) is effected by thepad-dyeing process.
 8. A method according to claim 1 wherein fluorescentwhitened polyamide fibre material is treated.
 9. A method according toclaim 1 wherein polyamide fibre material that has been dyed withreactive or disperse dyes, with the exception of metal complex dyes, istreated.
 10. A method of improving the fastness to ozone, NO_(x) andchlorine of natural or synthetic polyamide fibre material that isundyed, fluorescent whitened or dyed with reactive or disperse dyes,with the exception of metal complex dyes, wherein the fibre material istreated with a liquor comprising a compound of formula (1)Y₁—X—Y₂  (1) wherein X is a divalent aliphatic or cycloaliphatic radicaland Y₁ and Y₂ are each independently of the other —OH, —CO—OR₁, —NR₁R₂,—CO—NH—NR₁R₂ or —NH—CO—NH—NR₁R₂, wherein R₁ and R₂ are eachindependently of the other hydrogen; C₁-C₁₂ alkyl unsubstituted orsubstituted by one or more hydroxy, amino or carboxyl groups or halogenatoms C₅-C₂₄ aryl unsubstituted or substituted by one or more hydroxy,amino or carboxyl groups or halogen atoms; C₆-C₃₆ aralkyl unsubstitutedor substituted by one or more hydroxy, amino or carboxyl groups orhalogen atoms; or C₅-C₂₄ cycloalkyl unsubstituted or substituted by oneor more hydroxy, amino or carboxyl groups or halogen atoms.